Financing Receivables - Schedule of Aging Analysis of Financing Receivables (Details) - USD ($) $ in Millions	Oct. 26, 2019	Jul. 27, 2019
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 1,585	$ 1,643
Current	8,267	8,394
Total	9,852	10,037
Nonaccrual Financing Receivables	38	47
Impaired Financing Receivables	38	47
Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	404	503
Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	329	240
Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	852	900
Lease Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	379	434
Current	1,705	1,796
Total	2,084	2,230
Nonaccrual Financing Receivables	24	13
Impaired Financing Receivables	24	13
Lease Receivables | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	91	101
Lease Receivables | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	73	42
Lease Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	215	291
Loan Receivables
Financing Receivable, Past Due [Line Items]
Total Past Due	542	662
Current	4,793	4,776
Total	5,335	5,438
Nonaccrual Financing Receivables	11	31
Impaired Financing Receivables	11	31
Loan Receivables | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	173	257
Loan Receivables | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	127	67
Loan Receivables | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	242	338
Financed Service Contracts
Financing Receivable, Past Due [Line Items]
Total Past Due	664	547
Current	1,769	1,822
Total	2,433	2,369
Nonaccrual Financing Receivables	3	3
Impaired Financing Receivables	3	3
Financed Service Contracts | Past due 31-60 days
Financing Receivable, Past Due [Line Items]
Total Past Due	140	145
Financed Service Contracts | Past due 61-90 days
Financing Receivable, Past Due [Line Items]
Total Past Due	129	131
Financed Service Contracts | Past due 91 or above days
Financing Receivable, Past Due [Line Items]
Total Past Due	$ 395	$ 271